Abstract
AbstractA double tubed coaxial line type microwave plasma CVD system has been developed for a‐Si:H film deposition using hydrogen and argon gases with pure SiH4 gas as the material gas. The film quality was evaluated as a function of the plasma condition.Since the spreads of hydrogen and argon plasmas were in the range of 2‐3 cm and 8‐9 cm, respectively, the substrate was placed 10 cm from the end of the discharge tube to avoid bombardment of the substrate by high‐energy particles. The film fabricated under hydrogen plasma showed superior characteristics. The film deposited at the substrate temperature between 150 and 200°C were of high quality; predominantly SiH bond rather than SiH2 bond, a large value for the photo‐dark conductivity ratio (σp/σd − 105) and a small density of dangling bonds.A high‐quality film can be fabricated under hydrogen plasma because a large amount of hydrogen radicals covers the film surface, thereby causing a thermal structural relaxation of silane radicals. This relaxation results when the silane radicals increase their surface mobility after the soft landing on the film surface.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call